University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 5-2013 Conductive Textiles and their use in Combat Wound Detection, Sensing, and Localization Applications Stephen A. Holland [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Electrical and Electronics Commons, and the Electromagnetics and Photonics Commons Recommended Citation Holland, Stephen A., "Conductive Textiles and their use in Combat Wound Detection, Sensing, and Localization Applications. " Master's Thesis, University of Tennessee, 2013. https://trace.tennessee.edu/utk_gradthes/1627 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Stephen A. Holland entitled "Conductive Textiles and their use in Combat Wound Detection, Sensing, and Localization Applications." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Electrical Engineering. Aly E. Fathy, Major Professor We have read this thesis and recommend its acceptance: Benjamin J. Blalock, Jeremy H. Holleman Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) CONDUCTIVE TEXTILES AND THEIR USE IN COMBAT WOUND DETECTION, SENSING, AND LOCALIZATION APPLICATIONS A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Stephen A. Holland May 2013 ii Copyright © 2013 by Stephen A. Holland All rights reserved. iii ACKNOWLEDGMENTS I would like to extend my deepest gratitude to my advisor, Dr. Aly Fathy, who began working with me as an undergraduate and helped transform me into a researcher. He willingly brought me into the exciting realm of microwave technologies and allowed me to combine his area of expertise with other exciting advancements in electrical engineering. He has helped me understand the importance of balance, not only in work but also in life. He helped me maintain my focus while I juggled the completion of numerous, concurrent research activities. The Safeguards and Security Technology Group at Oak Ridge National Laboratory (ORNL) provided the original motivation and opportunity for me to pursue this work for my graduate studies through a project setup with the University of Tennessee, Knoxville. Through ORNL, I was given the opportunity of leading a research effort to develop systems that utilize conductive fabrics for nuclear safeguards and security applications. I would like to thank Chris Pickett, group leader of the Safeguards and Security Technology Group, for his guidance and direction. Chris and Jim Radle worked closely with our government sponsor, the National Nuclear Security Administration’s Office of Nuclear Verification (NA-243), to ensure our research efforts met the expectations and mission of NA-243. Additionally, I would like to thank my mentor, Dr. Michael Kuhn, and Nathan Rowe for guiding me as I worked to develop a sensing method for conductive textiles that allows the distributed resistance to be measured and the location of tamper or penetration determined. They worked with me to ensure we developed a robust sensing system and obtained useful, real-time iv experimental results. I would also like to thank Cody Mahan for his assistance while he completed a summer internship at ORNL. Additionally, I extend sincere appreciation to the microwave and antenna group at the University of Tennessee, Knoxville. My thanks go to Dounia Baiya for helping with the textile antenna designs and to Essam Elkhouly for agreeing to test the completed antennas on his indoor localization system. I would also like to thank to the group’s graduate researchers for their support and encouragement. The ideas and challenges presented by each of my mentors and peers throughout this research have allowed me to develop useful research for various applications including combat wound detection and localization. v ABSTRACT Conductive textiles, originally used for electromagnetic shielding purposes, have recently been utilized in body area network applications as fabric antennas and distributed sensors used to document and analyze kinematic movement, health vital signs, or haptic interactions. This thesis investigates the potential for using conductive textiles as a distributed sensor and integrated communication system component for use in combat wound detection, sensing, and localization applications. The goal of these proof-of-concept experiments is to provide a basis for robust system development which can expedite and direct the medical response team in the field. The combat wound detection system would have the capability of predicting the presence and location of cuts or tears within the conductive fabric as a realization of bullet or shrapnel penetration. Collected data, along with health vitals gathered from additional sensors, will then be wirelessly transmitted via integrated communication system components, to the appropriate medical response team. A distributed sensing method is developed to accurately predict the location and presence of textile penetrations. This method employs a Wheatstone bridge and multiplexing circuitry to probe a resistor network. Localized changes in resistance illustrate the presence and approximate location of cuts within the conductive textile. Additionally, this thesis builds upon manually defined textile antennas presented in literature by employing a laser cutting system to accurately define antenna dimensions. With this technique, a variety of antennas are developed for various purposes including large data transmission as would be expected from multi-sensor system integration. The vi fabrication technique also illustrates multilayer antenna development. To confirm simulation results, electrical parameters are extracted using a single-frequency resonance method. These parameters are used in the simulation and design of single- element and two-element wideband slot antennas as well as the design of a wideband monopole antenna. The monopole antenna is introduced to an indoor ultra-wideband (UWB) localization system to illustrate the capability of pinpointing the wearer of textile antennas for localization applications. A cavity-backed dog-bone slot antenna is developed to establish the ability to incorporate conductive vias by sewing conductive thread. This technique can be easily extrapolated to the development of textile substrate integrated waveguide (SIW) technologies. vii TABLE OF CONTENTS Chapter Page CHAPTER I: Introduction and Motivation ........................................................................ 1 Introduction to Combat Wound Detection .................................................................. 3 Conductive Textile Fabrication ................................................................................... 5 Metallization Process ............................................................................................ 8 Organization of the Thesis ....................................................................................... 11 CHAPTER II: Literature Review .................................................................................... 14 Conductive Textile Sensor Development ................................................................. 14 Conductive Textile Antenna Development ............................................................... 20 CHAPTER III: Materials ................................................................................................. 32 Conductive Textiles .................................................................................................. 32 Dielectric Materials ................................................................................................... 34 Fabric-Based Sensor Materials ................................................................................ 36 Adhesive Materials ................................................................................................... 36 CHAPTER IV: Using Conductive Textiles as Fabric-Based Sensors ............................ 41 Distributed Fabric-Based Sensor Development ....................................................... 41 Resistance Network Theory................................................................................ 42 First Generation Fabric-Based Sensing System ................................................. 49 Comparison between First-Generation Fabric-Based Sensor Experimental Results and Computer Model Expectations .................................................. 54 Second-Order Discrete Laplacian Mask ............................................................. 59 Second-Generation Fabric-Based Sensor .......................................................... 65 Variability Assessment ....................................................................................... 79 CHAPTER V: Using Conductive Textiles for Microwave Applications ........................... 85 Precise Antenna Fabrication Using a Laser Cutter .................................................